I use a 16" pizza pan (crisper) with holes in it I picked up at Wally World. Use it on the third rack. Works well in keeping temps consistent. I've tried lager coal baskets, smaller coal baskets different lids, as well as grill heights and the pan works the best. Mine (UDS) looks like a rookie mistake compared to some I've seen. Still works though.
Small Charbroiller, 40 year old barrel pit, UDS, 97 Weber Performer, Brinkman gas grill.